1. Field of the Invention
The present invention is generally in the field of semiconductors. More specifically, the present invention is in the field of fabrication of compound semiconductors.
2. Background Art
One of the challenges encountered in III-nitride semiconductor device fabrication centers on doping of a III-nitride semiconductor body without compromising its stoichiometric integrity. Specifically, it is known that at high temperatures, for example temperatures greater than approximately 800° C., nitrogen may escape from the III-nitride body, resulting in its decomposition.
Nevertheless, important steps in the semiconductor device fabrication process require processing at high temperature. For example the annealing step relied upon to repair implantation damage, as well as to activate dopant ions, typically requires such high temperatures. As a result, the relatively low decomposition temperature of III-nitride semiconductor materials presents a technical barrier to performance of the dopant implantation and annealing processes commonly used to form P-N junctions in a semiconductor body.
One conventional approach to overcoming, or at least circumventing, the problem of III-nitride doping utilizes a technique of growing the dopants into the III-nitride body as it is formed, rather than performing a dopant implantation. A significant drawback of that approach, however, is that the doping performed in that manner results in relatively homogenously doped layers of the III-nitride body. As a result, differential doping is effectuated only vertically, so that spatially selective doping in the lateral direction cannot be achieved directly through growth.
Thus, there is a need to overcome the drawbacks and deficiencies in the art by providing a solution that enables laterally as well as vertically selective spatially defined doping of a III-nitride semiconductor body, while maintaining the structural and stoichiometric properties of the semiconductor material.